Furnace



(No Model.) 2 Sheets-Sheet 1.

E. B. GOXE. FURNAGB.

No, 499,716. Patented June zo, 189s.

W4 @JWM (No Modem' 2 sheets-sheet 2. E; B. GOXE.

FURNAGE.

No. 499,716. Patented June 20, 1893.

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I Le i i i fvg UNITED STATES PATENT OFFICE.

ECKLEY B. COKE, OF DRIFTON, PENNSYLVANIA.

F'uRNAoE.

SPECIFICATION forming part of Letters Patent No. 499,716, dated J une 20, 1893. Application filed November 16, 1892. Serial No. 452,202. (No model.)

To all whom it may concern:

Be it known that-I, ECKLEY B. OOXE, a citizen of the United States, residing at Drifton,`

in the county of Luzerne and State of Penn- Sylvania, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

This invention relates to furnaces for burning coal and other fuels; it being intended more especially for burning the finer kinds of anthracite coals, among which are those known in the market as pea coal, buckwheat coal, &c.

The object of my present invention is to furnish an improved furnace adapted for burning completely and economically fuels such as described, and to carry out the process therefor described in my prior application, Serial No. 448,048, filed October 6, 1892.

In the drawings accompanying and forming a part of this specification, Figure 1 is a sectional side elevation of a furnace embodying my present improvements. Fig. 2 is a vertical transverse section of the furnace, in linea a, Fig. 1, showing the parts at the righ-thand of said line. Fig. 3 is a plan view'of the blast-chamber of the furnace. Fig. 4 is an end view of said chamber. Fig. 5 is an end View of one of the grate-bars; Fig. 6 an edge or side view of the same, and Fig. 7 a plan View. These three views are drawn in projection, after the usual arrangement of detail construction drawings. v

Similar characters designate like parts in all the figures.

The furnace illustrated in the drawings is shown underneath a steam-boiler, B, which may be of any well-known type; or, said boiler may be replaced by any other thing to be heated. The furnace has the usual inclosingwalls at the sides and ends thereof, and (in the absence of a steam-boiler or other device to be heated over the furnace) the ordinary top-covering. In the drawings, the side-walls are designated in a general way by 2 and 4, respectively, and the furnace-chamber, C, is shown covered by a steam-boiler, B. At the forward end of the furnace-chamber, this is provided with the end-wall 3, through which is a passage-way at 5 for the supply of fuel to the grate, said supply being delivered from a suitable hopper or other source of fuel supply, as H. At the rearward end of the furnacechamber, this is shown provided with a bridgewall, 7, which is connected with a vertical wall, 8, rearward of the traveling-grate. Said hopper is shown having a chute comprising the inclined upper and lower walls 5 and 5, respectively, for delivering the fuel from the hopper through said opening in the wall 3, to

the grate G.

rlhe upper side, or floor, of the furnacechamber C is formed of the fuel-carrying run, 10, of an endless traveling-grate, designated in a general way by G, and preferably composed of a series of similar grate-bars, or sections, 9, pivotally connected and carried bythe wheels 12 and 14, that are fixed on the two shafts 13 and 15, respectively. The ends of the" several grate-bars are shown supported by guides,of which those for the upper or fuel-carrying run of the grate are designated by 16 and 18, while thos for the lower or return-run 11 are designatedby 17 and 19, respectively.

A suitable construction of the grate-bars is shown in. the detail views, Figs. 5, 6 and 7. In Fig. 7 is shown a plan View of the gratebar, or section,consisting of the three similar bars 27, which are shown widest on their upper sides and having between them the airspaces 28, the ends of said bars 27 being connected by the end-bars 29, which have on one end thereof the projecting hinge-pieces 29 and on the other endr the corresponding notches 29" for receiving the similar hingepieces of another gratesection. This arrangement Will be understood by comparison of said detail views with the traveling-grate shown in Fig. 1. In the under side of the grate-bal', or grate-section, there is formed in the end-bars thereof the notches 30 for engagin g the corresponding cogs 33 of the chainwheels 12 and 14 (Fig. 1) when the grate is driven forward.

While I have thus particularly described the construction of the traveling-grate herein shown, it is not to be understood that such detail construction is essential to my invention; for any other suitable form of traveling-grate may be substituted for the one herein shown and described, without departing from the spirit of my invention; provided, of course, that the co-acting parts and accessories of the furnace be of suitably modified construction.

For protection, in practice, of the ends of the grate-bars, and also for preventing the ne fuel passing over the ends thereof, the side-walls of the furnace are brought over the grate-bar as shown in the sectional view, Fig. 2, the brick-supporting plates, 20'and 22, of the side-wall extending over the grate-bar by a distance equal to, or greater than, the width ofthe end-bar 29 of the grate-section.

Under the upper or fuel-carrying run, l0, of the traveling-grate is a series of air-supply chambers,v a, h, c and d, located at successive points of the length of the furnace-chamber. The air-supply chambers may be two or more in number, four of them being shown in the present instance; in general, I prefer to use not less than three such chambers. Each of said successive chambers is to be suitably supplied with air, which may be done by blowing the air thereinto through corresponding pipes, a, b, c and d', shown in end view in Fig. l, said pipes being supplied by some suitable blower not shown. The divisional walls between the several airsupply chambers come up close to the under side of the upper run of the traveling-grate, so as to practically close the chambers the one from the other, with the exception of a slight leakage insufficient in practice to materially affect the operation of the furnace.

For supplying air to the several chambers a, b, c and d, respectively, the pipes ct', b', c and d', leading to said chambers respectively, are shown provided with some suitable regulating-valves, or gates, as a, b, c and d, respectively; which valves, as indicated by the dotted lines in Fig. 3, are shown set at Varying positions, the valve et being shown fully open, and each succeeding Valve being opened to a lesser extent. By this means the air-pressure in the successive chambers may be independently regulated as required for the proper carrying out of the process hereinbefore mentioned.

The fuel is fed to the grate at a point adjacent to the first air-supply chamber, each section of the grate receiving its fuel at or before the time it reaches the first air-supply chamber @,bein g then carried along over that chamber and the succeeding chambers b, 0 and d; during this period the combustible material of the fuel is consumed, and the resulting cinder or ash is afterward carried under the bridge-wall 7 and finally delivered over the rearward end of the grate into the ash-pit 2l. In practice, the combustion goes on, at one stage or another, throughout nearly the entire length of the furnace, the ignition taking place within a short distance of the point Where the fuel falls upon the grate, this being completely reduced to cinder over the last chamber, d, of the series. The reduction of the fuel by combustion gradually lowers the same on the grate, (by an amount depending on the nature of the'fueL) so that at the point, 23, where the cinder passes under the bridge-wall, the thickness of the cinder is generally much less than the original height of the fuel, as illustrated in Fig. l. The cinder or ash, 24, over the last chamber, d, of the series of air-suppl y chambers being blown for a short time after the combustible is burned therefrom, is cooled down to a relatively low temperature before it passes under the bridgewall and is discharged from the grate. By this means two economies are effected; irst, the air enteringlthe furnace-chamber from said supply-chamberd is heated; and second, this heating is effected by the heat of the cinder, which would otherwise be lost; this statement applies also to the grate itself, which is thus cooled at the earliest practicable m0- ment and before it reaches the driving-wheels l2 and 14, so that the driving mechanism will be heated to the least possible degree. Another feature of the organization described is that the air from the last supply-chamber, after being heated by taking up the heat of the grate and the cinder, is mingled with the partially consumed gases from the more forward portions of the furnace-chamber, and serves to effect the complete combustion of these gases. The cinder carried forward upon the traveling-grate, under the wall 7, at the Arearward end of the grate, as shown at the left-hand in Fig. l, is discharged from the grate-sectionv into a pile,.wl1ieh may be removed, from time to time, by any convenient means, without interrupting the operation of the furnace.

The yparticular amount of air-pressure required in the respective air-supply chambers will be governed by the kind and mechanical condition of the fuel but the proper relation of the several air-pressures may be expressed by a formula as follows: Let x represent the normal pressure of the air-supply in the chamber a. Then -y will represent the air-pressure in the second chamber, b; y being the difference between the pressures in the two chambers. The air-pressurein the third chamber will be equal to the pressure in the rst chamber less a quantity greater than y, and

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may be represented by 0:- (y-t-a). Following this method of illustration further, the pressure of the air-supply in the next chamber, d, will be represented by m- (y--a-l-b). In practice, the quantities y, a and b may sometimes be equal, or substantially so; or, these characters may in the formula have different Values; and the pressure in the second chamber may be greater than in the irst chamber.

After the furnace has been put into complete operation, the fireman, by occasional observation of the burning fuel through observation-doors at 25 and 26 in the side-wall of the furnace, can, by means of the air-Valves in the pipes c', b', c and d', readily regulate or vary the pressure in the successive air-chambers so as to produce the best results and completely reduce the fuel to cinder before it reaches the wall 7. By this means the entire iioor of the furnace-chamber may be kept covered, and the combustible of the fuel may be consumed with a high degree of economy.

One of the principal objects of my improvements is to furnish an effective means for s0 controlling the consumption of fuel in a furnace of a given size as to regulate as required the quantity burned in a given time. By means of these improvements the consumption of fuel maybe graduated from time to time exactly as required by changes in the amount of steam drawn from the boiler. By increasing the air-blast during the middle portion of the combustion-period, the fuel will be more readily consumed; or, by decreasing the pressure in the rearward air-su ppl y chambers, the grate may be traveled more slowly and the combustion prolonged so as only to consume the combustible of the fuel just before the cinder passes under the bridge-wall. The regulation of the duration of the period of combustion as herein described permits a variation in the power of the steam-plant ywithout interfering with the regularity of the furnace operation or the completeness and economy of the consumption of the fuel.

The air-chambers, a, b, c and d, are shown separated by the division-walls 31, at whose upper edges are cut-off plates, 32, of a width in excess of one of the air-spaces 28 of the grate. By this means, when said partition- Walls are of ordinary thickness and the said air-space is of a width equal to or greater than said thickness, the air-space is prevented from making a communication between two successive air-chambers, as will be understood by inspection of Fig. 1, in which the particular air-space 2S is shown closed by one of the cut-o plates 32.

As a means for driving the Wheels 12 and 14 to actuate the grate as required, the shaft 13 is shown furnished with a worm-Wheel, L10, Iixed thereon, which Worm-wheel engages with the corresponding worm 41 carried by a driving-shaft, 42, which is supported in suitable bearings, as 43, and is operated by means of an ordinary pulley, 4:4; Other shaft-driving mechanism may, however, be substituted for the worm-gearing described; but in practice I find this gearing to be very suitable for the work.

That feature of the apparatus shown in the drawings of this application, and which consists in the inclined Wall or block over which the coal is delivered to the furnace-chamber and onto the traveling grate for exposing the fuel to the action of the heated gases before its delivery upon the grate, is reserved to constitute in part the subject-matter of a separate application, Serial No. 472,891, tiled May 3, 1893.

Having thus described my invention, I claim- 1. In a furnace, the combination with a traveling-grate, of means for supplying fuel to the grate, and successive air-supply chambers below the grate, substantially as described.

2. In a furnace, the combination with a traveling grate, of successive air supply chambers underneath the grate, and means for independently regulating the air-pressure in said chambers, substantially as described.

3. In a furnace, the combination With an endless traveling-grate, of air-supply chambers Linder the fuel-carrying run of the grate, and means for reducing the air-pressure in one or more of said chambers below the pressure in another of the chambers, substantially as described.

4. In a furnace, the combination with the endless traveling grate, of grate-actuating mechanism substantially as described, a series of air-supply chambers underneath the fuelcarrying run of the grate, means for regulating the pressure of lair in said chambers to produce dit'ferent pressures in the different chambers, and means for supplying fuel to the grate at a point adjacent to one of said chambers, substantially as described.

5. In a furnace, the combination with al traveling-grate comprising a series of gratebars having air-spaces between said bars, of a series of separate air-supply chambers having the cut-off plates underneath the grateand of a width covering ono of the air-spaces of the grate, substantially asy described.

6. In a furnace, the combination with a traveling-grate, of a series of air-supply chambers under the grate, separate airsupply pipes for each chamber, and a regulatingvalve in each of the supply-pipes, whereby the pressure in each of the chambers may be independently regulated to produce different pressures in the different chambers, substantially as described.

7. The improved furnace herein described, consisting in the combination with the furnace Walls and chamber, of a traveling-grate, and separate variable-pressure air-supply apparatus under successive portions of the furnace-chamber and below the grate, substantially as described.

ECKLEY B. OOXE.

Witnesses:

` E. B. ELY,

ELLIOTT A. OBERRENDER.

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